Liquid level indicator



Oct. 28, 1952 E. R. KlLsBY 2,615,338

LlQUID LEVEL INDICATOR my 1 i @gw ATTORNEY Oct.'28, 1952 E. R. KILSBY 2,615,338

LIQUID LEVEL INDICATOR Filed Aug. 1e, 194e 2 'SHEETS-.SHEET 2 Z DW/mea /Q A74 55) ATTORNEY Patented ont. 2s,- '1952 l 2,615,338Vv lEdward R. Kilsby, Newark, N. JL, assignor to Fos- ,-ter -Wheeler Corporation; New York, N.r vY., a.

, corporation of New York Apnl'icaiinn Augustv 16, 194e, sain; Nessuna f This invention relates in liquid level indicators and more particularly to'- a liquid level indicator for indicating` the lev'el in a vessel containing vapor and liquid or vapor laden or emulsionlike mixtures oiliquid-and vapor.

' accurate visible indicatio'nof the height Aor surface position'of arliquid or'- mixture of vapor and liquid iri afvesselis not obtainable with'the usualliquidvrlevel indicating gauge' because the density of the vapor-laden liquid in-the drum` is different from the density of the liquid in gauge.

The-'difference in density occurslbecause r.the

liquid! inthe gauge, which "gauge Ais normally lo.- catedk a `distance fromv an vouter Wall of the vessel, is substantially vapor free .and cooler than the mixture of vapor and `liquid in the" vessel; This is the cause of la substantiali ygauge error.

The present invention provides" aliqud vlevel indicator lforaccurately determining the liquid level ina vessel containing alvapor and liquid mixture, L, i 1 z The invention will be disclosed asapplied to a steam'and .water drum of. -a i. steam generator to indicate the water level-innsaid drum but it will accurately indicating theA :liquid level in vessels containing a mixture of vapor and liquids generally. f f This" invention will ybe understoodA from the followingdescription when consideredl in connection with the accompanying drawings in which: l,

Fig.. 1 is almorevor less'diagrammatic vertical sectional view ofthe present invention applied to the steam-and Waterfdrum. of--a steam generator; Fig. ,2 is an elevational view ofi'the invention associated with the steam and water drumof a steam generator; y i .l Fig. 3 is al horizontal sectional View taken on the linei3-V-3 of Fig. 2.;

Fig. 4 is a view similar to Fig 2 but of another embodiment of the invention, vand A.

Fig. 5 is a vertical lsectional view of a further embodiment of the invention.

or similar parts throughout the several views.

Referringito the drawings, the gauge of the present invention is Ydesignated'igenerallydoy thev Like characters -of reference refer to the same v(Fi-g. 3). .plurality of riser tubes I9 and downcomer tubes b'e understood that theffinventionfis capable of l tionship by bolts .23".

tiallyhorizontally extending tubes I2. Each of i the'tubesy I2, as shown, communicates with the gauge'body I1 through a valve controlled L-connection I6 and-'ihorizontally extending tube I5 The steam and water drum II has a I'B through whichfluid circulates'and also has oneor morefsteamfoutlet ltubes' 20. Thc'fgauge `Ill comprises a body I1 extending Vina' substantially'ivertical'plane which body iicemberY has vertical vvvvater passage I8 extending -iongi'tudinally"thereirr Tubes I5 are connected tothe bodymember I1 and are in communication 'with the passage I8 through inlet ports 21 in the body member i1. lElongated pieces of gauge glassZ'I- are secured' along-opposite sides of thev body member I1 adjacent passage 'I8 bysecuring members 22 having vision slots' 22 therein, the members 22 being heldin position by bolts 23. Each ofthe glassrstripsZI has-a piece oflrmica 2 I at the side thereof adjacent the passage I8. Suitablegaskets 26'"=are'interposed between members 2v2 and'v glass 2| sof'. that the glass, themembers 22 and ythe member I1 are heldin huid-tight rela- The passage' I8 in body member I1 isi'in communication at the top thereof 'through'con'duit I3icont`rolled by a valve I4 with thefste'amspace:inithe' upper part of drum II..

A Adrain24 is connectedto the bottom of passage In. operation, vvateriis admitted into the drum IfI througha feed vwater linei notshown, until a: proper water level inv the vdrum is obtained. The feed .water .from the drum is fed to the tubes of Aifhevapor"generating'not showngthrough down- Ic'omers:;I9 and'steamgenerated rises intermixed withl liquid. through V"rise'r tubes I9. Steam thereafter is'fcontained in theiupper part of .the drum- ,above the surface level SLi while below saidsurface level there is a 'bodyof steam laden Water. The steam laden water flows into the .passage liirinxthe gauge body; I'1through upper Itubes'Z',45 (see Fig. 1) andinletp'orts 21, to thereby indicate through gaugefgla'ss 2l in gauge :ID the; level of steam laden water `in the drum..

Since thegauge vIis normally spaceda substan- ,tial distancefromithe end of the drum II, some hea-tis givenup by `the steam laden water in flowing through the tubes I2 and I5 so that the water in the passage I8 of the gauge is substan- .tial-ly stea-ini-freea-,but atr the :level ofvthe upper- .mostiIm'beszfll ityi's" at .substantially the same temperature' as ,ft-he mixture in the drum. vThe Water.,flowing-between drum vI-I and passageqIS offithe gauge. to' passes ,'throughinlet ports `21 at a plurality of closely spaced levels. As the water in passage I8 continues to cool, its density increases causing it to ilow back through the lower of tubes I5, I2, into steam and water drum II wherein the heights of the mixture above the lower tubes I2 does not provide a hydraulic or hydrostatic pressure equal to that provided by the more denseuid in passage `I8. VFlow from passage' I8'to steam and'water drum A-II through t lower tubes I2 tends to lower the height of the column of fluid in passage I8, causing fluid tol.,

flow through the upper of tubes I2, I5 from the steam and water drum into passage YI8. Thus the passage I8 may be Aconsidered as containing fluid of least density at the top thereof, with'suchuppermost iluid continually replenished through In rsuch construction, the gaugeof the present int vention would not indicate the water level in the drum erroneously, regardless of the densityof the steam laden water inthe drum, by more than approximately'one inch to one and one-half inches. The above .examplel is given merely to illustrate the operation of the present invention and is not tov have a limiting veffect', thereon. It willl be understoodl thatA the dimensions given are given merely by way of illustrationand are not'to have a limiting effect on the scope of the invention.

. vReferring to Fig. 4 of the drawings in the embodiment of the invention disclosed therein, the gauge I I) hasa residue collecting chamber or container 3'I positioned in spaced relationship to the end of the drum and intermediate said gauge and Ythe adjacent end of the drum II. As shown, the chamber 3'I- has connections or uid outlets 31 to which a gaugeglass structure, not shown, may .be attached if desired. Tubes I2, which are arranged in substantially the same manner as in' the embodiment of the inventiondisclosedin Figs. l to 3, are in communication with they container 3I while pipes I2' are each connected at one end to said container` and at the opposite end to valve controlled L-connection IB. As in the form of the invention shown in Figs. 1 to 3, tubes I5 communicateV at the opposite ends thereof with the L-connection I6 and the body member I'I of gauge I0. Container 3'1 is in communication with the line I3 through conduit *25.

In operation ofv the embodiment of the invention shown in Fig. 4, steam laden Water flows from the drum vII through thetubes I2 'thence into the container 31. Residue in the steam laden water settles in the residue` collecting container or chamber 3'I and water from which-residue has settled vthereafter passes through pipes I2', L-connections I6, tubes I5-and into passage I8 in the gauge I0. The operationotherwise is substantially the same as the operation of the.

embodiment of the invention disclosed in Figs. 1 to 3.

Referring to Fig. 5 of the drawings, the embodiment of the invention disclosed therein comprises a liquid level indicating gauge having a container 28 with a fluid space 29 therein. A passage 30 is formed alongone side and outside the space 29 of the container`28 by a body mem- 4I2 in Fig. l. .tion with the-passage 30 through a plurality of 4 ber 3I attached to the outer wall of the container in a fluid-tight manner, the outer wall of the container forming one side of the passage While the opposite side thereof is formed by a strip of glass 32. The glass is held in position in a'fluidtight manner by a clamping member 33 secured to the body member 3i byv bolts 34. A gasket 35 Vis, interposed jbetween,-the clamping member 33 and the glass 32.;l Like- .pa'ssage I8y ofthe gauge I0 shown in Fig. 2, fluid space 29 of the con- `tainer 28 is in communication with a drum II through the spaced tubes I2 which are arranged in substantially the same manner as the tubes Fluid .space 29 is in communicaports 36 through the side wall of container 28 and are disposed in spaced relationship to one another and in substantial horizontal alignment with an adjacent tube I2 in the other side Wall of said container.

The operationof vthe embodiment of .the invention shown in' Fig. 5 is similar to the operation fes of Lthe embodiment shown in Fig. 2 except that the liquid from drum I I flows into the fluid space 29 of the container 28 whence it passes through ports 3B into passage 30. iThe liquid level in the passage 30 is visible through the glass strip 32. The operation of this embodiment of the invention is otherwise Vsubstantiallythe same as the operationof kthe embodiment shown in Figs. 1 to 3. Y v

Inasmuch as various changes may be made in the form, location and arrangement of the operation of the apparatus disclosed without departing v from the principles of the4 invention, it will be understood that the invention is not to be limited excepting by the' scope `of the appended claims.

What isclaimed is: i v

1. An indicator for indicating the level of vapor-laden liquid in a lvapor and liquid drum of a vapor generator which drum has a vapor space above a normal vapor-laden liquid level in the drum and a vapor-ladenliquid space below-said level, said indicator being'positioned outside the drum in spaced relationship thereto, the indicator comprising a gauge body having a substantially vertical 'passage,v af plurality of conduits, one of said conduits being in communication with the drum adjacent the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, another of said .conduits being in communication with the drum adjacent the lowermost point at which the vapor-laden liquid is to be visibly indicated and intermediate conduits in communication with-the drum 'at vertically spaced points intermediate said uppermost and lowermost points,4 each conduit being in communication with said' passage'at a point in substantially the same horizontal planeas its point of communication with the drum, indicating means communicating with said passage and 'adapted tonvisibly indicate the level of vaporladen liquid therein iatany level between said uppermost and lowermost levels, and a pressure equalizing connection between the vapor space of Vthedrum and the upper part of the indicator passage. f l

y"2. An yindicator for indicating the level of vapor-laden liquid in a. vapor and liquid drum of a vapor generator which drum has a vapor space above a normal vapor-ladenliquid level in thesdru'm and a vapor-laden liquid space below said level, said indicator being positioned outside the drum in spaced relationship thereto, theindicatorkcomprising Va lgaugefbody having a substantially' vertical passage,' av plurality l of con# duits,'oneof said conduits being infcommunica'- ladenv liquid level and 'adjacenttheuppermost point at which the vapor-laden liquid? inthe drum is to be visibly indicated, another of said-conduits being in communication with' the drum below saidnormal vapor-laden liquid level andiadjacent the lowermost point at which-the vapor-laden liquid` is to be visibly indicated and intermediate conduitsin communication with'the drum `-at ver-1.

tically spaced points intermediate said uppermost and lowermost points, each conduit being in come munication with said passage-at a pointlin-substantially the same horizontal plane asfits point of communication with the drum, level indicating 1 means l`communie'atin'gY with fsaid passage and -adaptedto visibly' indicate the level of vaporl'aderi-fliquid therein at any level between'said uppermostl and lowermost levels,` and a pressure equalizinr'g connection between the vaporr space' of,l the drum vand 1 the indicator passagejabove sa' uppermost point. 1 '-3=."An indicator for r`indicating the level' of vapor-laden liquid in a vapor and liquid/drum of a vapor generator, which drum has a vapor space above a normal `vaqzaor-laden liquid level in the drum 'and a vapor-laden liquidspace belowsaid level, said indicator being positioned'outside lthe drum-5in spaced relationship theretoy-the indisaiduppermost and-lowermost points', each con-r duitjbeing in. communication at the opposite end thereof Vwith-said passage at' a pointv in substan'` tially the's'ame horizontal plane asfits point of communication'with the drum, level indicating means communicating with' saidv passage,y and' adapted to visibly indicate Athe level of vapor;

laden liquid therein at any level lbetween said uppermost and 4lowermost levels, andA apres*-y sure equalizing connection betweenv the vapor space of-*the drum and the upper part ofthe indicator passage". f l

4. An indicator for; indicating the level'of vapor-laden liquid in 'a' vapor and liquid'drum of a vapor generator which drum has ajyv'a'porV space' above 'a normal"vapor-laden'lquid level i'n-the drum and avapor-laden' liquid'space below said level, said indica-tor being positioned out-` side the drum Vin spaced relationship thereto, thev indicator comprising-a gauge body having asubf` stantially vertical passage, a plurality of conduits;

onev of said -conduits'ebeing in communication with the drum adjacent theu'ppermost point" at which-the vapor-ladenliquid in thedrum' isl to be visibly indicated; anotherof said conduits beingV in communication with the drum adjacenty the.' lowermost point at v'which the vapor -laden liquid-*is to be visibly indicated andv intermediate conduitsrin communication with'the drum at`fver= ticallyvspaced ,pointsL intermediate said `upper-r' vmost and vlowermost points, eachl conduit bein n mummia-anon..witnfsaid passage at a@'point-fy amargas substantially 'the same horizontal plane as "its point of: communication with the drum, a gauge glass* communicating with 'said' passage .and ex-A tending at least between a level corresponding to the level of vthe point of communication of the conduit adjacent said uppermost level I'with said passage" andaV level corresponding to thelevel 'or the; point ofcommunication of the conduit ad-A jacent said lowermost level with said passage, and a pressurel equalizing connection. between7 the vapor spaceof the drum and the/upper part of the indicator passage.`

Ari indicator for indicating lthe .level 0f vaporeladen liquid in a vapor.; and liquid drum ofva'v'apor generator, which druml has avapor space above anormal vapor-laden liquid level in ,thev drum and a vapor-laden liquid space below said'level; said indicator being positioned outside tired-rum in spaced relationship thereto, the-"in-Y dicator comprising a gauge body having a substantially vertical passage, a plurality of conduits extending in vertically Yspaced horizontal planes, one of said conduits being in communication at one' end thereof with the'drum adjacent the up'- permo'st point at which the vapor-laden liquid in the drum is to be visibly indicated, anotherfof said' vconduits being in communicationat one end thereof'with the drum adjacent'thelowerm'o'st point at which the vapor-laden liquid is to 'be visibly indicated and intermediate conduits in communication at one end thereof-With the drum at vertically'jspaced points intermediate said up perinost and lowermost points, each conduitbe-y ing in communication at ther opposite `end thereof with said passage at a point in substantially the saine horizontalv plane as its point of communication with the drum, a gauge glass communicating with said passage and extending at least between a level corresponding to the level of the point of communication ofthe conduit adjacent said up-v permost level with said passage and a level corresponding to the level of the point of communication'of the conduit adjacent said lowermost levelhwith said passage, and a pressure eql'ializing connection between the vapor' space of the drum and the upper part of the indicator' passage.'v y

6.v An indicator for indicating the level of vapor-laden liquidin a'vapor and liquid drum of a vvapor generator which drum has a vaporspa'lce above' a normalvapor-laden liquidV level in the drum and a vapor-ladenk liquid space below said level, said indicator being positioned outside the drum in spaced relationship thereto, the 'indicator comprising a gauge body having a" substantially Verticalpassage, means forming a fluidtight chamber, said chamber being positioned in thes'pace between saidl indicator and the drum;

afplurality'of conduits, one of said conduits being in' communication with the drum adjacent the uppermost'point at which the vapor-laden liquid in the' drum is to be visibly indicated,` anotherv of'said conduits being in communication with the drum adjacent the lowermost point at which the vapor-'laden liquid is to be visibly indicated'and intermediate conduits in communication with the drum at vertically spaced points intermediate vsaid uppermostv and lowermostv points, eachl con--v duit beingin communication with said chamber at ,av point in substantially the same horizontal planeas its pointv of communication with the drum, a-y plurality Aof further conduits in communication with said chamber atone end thereof and with said passage'at theopposite. end there- .being in substantially the same horizontalplanes respectively. as the points of Vcommunication of said one conduit, said other conduit and said intermediate conduits with the chamber and with said drum,'level 'indicating means communicating with said passage and adapted to visibly indicate the level of vapor-laden liquid therein `at any level between said uppermost and lowermost levels, and a pressure equalizing connection between the vapor space of the drum and Athe upper part of the indicator passage.

'7. An indicator for indicating the level of vapor-laden liquid in a vapor and liquid drum of avaporgenerator which drum has a vapor space above a normal vapor-laden liquid level in the drum and a vapor-laden liquid space belowsaid level, saidindicator being positioned outside the drum in spaced relationship thereto, the indicator comprising a gauge body having a substantially vertical passage, means forming a fluidtight chamber, said chamber being positioned in the space between said indicator and the drum, a plurality of conduits, one of said conduits being Ain communication with the drum adjacent the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, another Vof said conduits being in communication with the drum adjacent the lowermost point at which the vapor-laden liquid is to be visibly indicated and intermediate conduits in communication with the drumV at vertically spaced points intermediate said uppermost and lowermost points, each .conduit being in communication with said chamber lat a point in substantially the same horizontal plane as its point of communication with the drum, a plurality of further conduits in communication with said chamber at one end thereof and with said passage at the opposite end thereof, the points of communication of said other conduitswith the chamber and with the passage being in substantially the same horizontal planes respectively as the points of communication of said one conduit, said other conduit and said intermediate conduits with the chamber and with said drum, a gauge glass communicating with said passage and extending atleast between a level corresponding to the level of the point of communication of the conduit adjacent saiduppermost level with saidpassage and a level'coro responding to the level of the point of communication of the conduit adjacent said lowermost lowermostqpoint at which the vapor-laden liquid is,to be visibly indicated and intermediate conlevel with said passage, and a pressure equali'zing connection between the vapor space of the drum and the upper part of the indicator passage.

8. An indicator for indicating the level of vapor-laden liquid in a vapor and liquid Adrum of a vapor generator which drum has a vaporY space above a normal vapor-laden liquid level in the drum and a vapor-laden liquid space below said level, said 'indicator being positioned outside the drum in spaced relationship thereto, the indicator comprising a gauge body having a substantially vertical passage, means forming a fluid space outside of said passage and extending longitudinally thereof, there being partition means between the passage and the fluid space, the fluid spacebeingincommunication with the passageA at different levels through a plurality of openings in the partition, -a plurality of conduits, one of said conduits being in communication with the drum adjacent the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, another of said conduits being in communication with Vthe drum adjacent the and lowermost points, each conduit being in y communication with said means forming a uid space at a point in substantially the same hori-` zontal plane as its point of communication with the, drum, level indicating means communicating withsaid passage and adapted to visibly indicate the level of vapor-laden liquid therein at any level between said uppermost and lowermost levels. and a pressure equalizing connection between the vapor space of the drum and the upper part of saidlindicator passage above said uppermost pointv Y Y .L f

9. Anindicator for` indicating the level of vapor-laden liquid .in a vapor and liquid drum of a vapor generator which drum has a vapor space abovea normal vapor-laden liquid level inthe drum and a vapor-ladenliquid space below said level, said indicator being positioned outside vthe drum in spaced relationship thereto, the indicator comprising agauge body having arsubstantially vertical passage, means forming a uid space outside ofsaid passage and extending longitudinally thereof, there being partition means between the passage and the uid space, a plurality of conduits, one of said conduits being in communication with the drum adjacent the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, another of said conduits being in communication with the drumadjacent the lowermost point at which the vapor-laden liquid is to be visibly indicated and intermediate conduits in communication with the drum at vertically spaced points intermediate said' uppermost and lowermost points, each conduit being in Communication with said means forming a uid space at a point in substantially the same horizontal plane as itsy point of communication with the drum, saidi uid space being in communication with said passage through a plurality of verticallypspaced openings in said partition means,

each'of the openings being in a horizontal plane corresponding to the horizontal plane of a point of communication of said conduits with the means forming a iluid space, indicating means communicating with said passage and adapted to visibly indicate the level of vapor-laden liquid therein at any level between said uppermostv and lowermost levels, and a pressure equalizing connection between the vapor space of the drum and the upper part of 4said indicator passage above said uppermost point.

10.*An indicator for indicating the level of vapor-laden. liquid in a vapor and liquid drum of a vapor generator which drum has a vapor space above a normal vapor-laden liquid level in the drum and a vapor-laden liquid space below said level, said indicator being positioned outside the drum in spaced vrelationship thereto, the indicator comprising a gauge body having a substantiallyv vertical passage, means forming a uid space outside of said passage and extending longitudinally thereof, there being partition means `between the passage and the uid space, a plurality of conduits, one of said conduits being in communication with the drum adjacent the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, another' of vsaid conduits being in communication with thedrum adjacent the lowermost point at which -Y the vapor-ladeulliquid is to be visiblyA indicated, and intermediate conduits in communication with the drum at vertically spaced points intermediate said uppermost and lowermost points, each conduit being in communication with said means forming a fluid space at a point in substantially the same horizontal plane as its point of communication with the drum, said fluid space being in communication with said passage through a plurality of Vertically spaced openings in said partition means, each of the openings being in a horizontal plane corresponding to the horizontal plane of a point of communication of said conduits with the means forming a fluid space, a gauge glass communicating with said passage and extending at least between a level corresponding to the level of the uppermost opening in said partition and a level corresponding to the level of the lowermost opening in said partition, and a pressure equalizing connection between the vapor space of the drum and the upper part of the indicator passage.

11. An indicator for indicating the level of vapor-laden liquid in a vapor and liquid drum of a vapor generator which drum has a vapor space above a normal vapor-laden liquid level in the drum and a vapor-laden liquid space below said level, said indicator being positioned outside the drum in spaced relationship thereto, the indicator comprising a gauge body having a substantially vertical passage, means forming a fluid-tight chamber, said chamber being positioned in the space between said indicator and the drum and at substantially the same level as the indicator, a plurality of conduits, at least one of said conduits being in communication with the vapor space of the drum and with said chamber, at least a second of said conduits being in communication with the drum. adjacent the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, at least another conduit being in communication with the drum adjacent the lowermost point at which the vapor-laden liquid is to be visibly indicated, and conduits intermediate said second and said other conduits in communication with the drum at vertically spaced pointsv intermediate said uppermost and lowermost points, each of the second, intermediate and other conduits being in communication with said chamber at a point in substantially the same horizontal plane as its point of communication with the drum, a plurality of further conduits in communication with said chamber at one end thereof and with said passage at the opposite end thereof, one of said further conduits eX- tending in substantially the same horizontal plane as the uppermost point at which the Vaporladen liquid in the drum is to be visibly indicated, another of said further conduits extending in substantially the same horizontal plane as the lowermost point at which the vaporladen liquid in the drum is to be visibly indicated, and intermediate further conduits eX- tending in horizontal planes intermediate the horizontal planes of said one and another further conduits, and level indicating means communicating with said passage-and adapted to visibly indicate the level of vapor-laden liquid therein at any level between said uppermost and lowermost levels.

12. An indicator for indicating the level of vapor-laden liquid in a vapor and liquid drum of a vapor generator which drum has a vapor space above a normal vapor-laden liquid level in the drum and a vapor-laden liquid space below said level, said indicator being positioned outside the drum in spaced relationship thereto, the indicator comprising a gauge body having a substantially vertical passage, means forming a fluid-tight chamber, said chamber being p0- sitioned in the space between said indicator and the drum and at substantially the same level as the indicator, a plurality-of conduits, at least one of said conduits being in communication with the vapor space of the drum and with said chamber, at least a second of said conduits being in communication with the drum adjacent the uppermost point-l at which the vapor-laden liquid inthe drum is to be visibly indicated, at least another conduit being in communication with the drum adjacent the lowermost point at which the vapor-laden liquid is to be visibly indicated, and conduits intermediate said second and said other conduits in communication with the drum at vertically spaced points ntermediate said uppermost and lowermost points, each of the second, intermediate and other conduits being in communication with said chamber at a point in substantially the same horizontal plane as its point of communication with the drum, a plurality of further conduits in communication with said chamber at one end thereof and with said passage at the opposite end thereof, one of said further conduits extending in substantially the same horizontal plane as the uppermost point at which the vapor-laden liquid in the drum is to be visibly indicated, another of said further conduits extending in substantially the same horizontal plane as the lowermost point at which the vapor-laden liquid in the drum is to be visibly indicated, and intermediate further conduits extending in horizontal planes intermediate the horizontal planes of said one and another further conduits, level indicating means communicating with said passage and adapted to visibly indicate the level of vapor-laden liquid therein at any level between said uppermost and lowermost levels, and a drain connection in communication with the lower part of said passage.

EDWARD R. KILSBY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 57,118 Githens Aug. 14, 1866 226,418 Purves Apr. 13, 1880 353,920 Cheek Dec. '7, 1886 1,669,110 Wencel May 8, 1928 1,962,187 Flock June 12, 1934 2,016,481 Brelsford Oct. 8, 1935 2,031,644 Gunderson Feb. 25, 1936 

